
Friends don’t let friends do keto. At least, that is if the friends are concerned about long term effectiveness and safety when it comes to body composition and health. An exception? Maybe if that friend suffers from epilepsy, migraines, or other neurological disorders (more on that below).
Like a drug, people seize upon the next quick-fix diet craze. Books are sold, talk show interviews occur, magazines run articles and headlines, devoted social media sites pop-up. But through all this fanfare…what does the research actually show concerning these diets? What does the research say about keto diets specifically?
What is the ketogenic diet?
The ketogenic diet is characterized by severe restriction of carbohydrates, generally to less than 50 grams per day, with calories coming predominantly from fat and protein (Barbanti, Fofi, Aurilia, Egeo, & Caprio, 2017). Lacking glucose for energy, fatty acids are removed from the fatty deposits within the body. These fatty acids are converted in the liver into ketone bodies, which then are utilized as energy as an alternative to glucose (sugar). A similar process in terms of using ketone bodies as a fuel source over glucose occurs during fasting (Barbanti et al., 2017).
The origins of the ketogenic diet: Not about ‘dem abs!
The ketogenic diet originated approximately a century ago (Kossoff & Cervenka, 2020). A Mayo Clinic researcher was interested in reducing the frequency of seizures in patients with epilepsy. Patients, who at that time, had limited medication options.
Fasting had gained attention during this time period as having protective effects against seizure activity (Kossoff & Cervenka, 2020). Dr. Russel Wilder believed that by following a high-fat, low-carb diet, the body could be put into a physiological state similar to fasting and thereby, reduce seizure activity without having to regularly undergo the discomforts of fasting. While more recent research has challenged the notion that the body enters into a state similar to fasting while following the keto diet, Dr. Wilder was correct regarding the diet’s ability to reduce seizure activity (Kossoff & Cervenka, 2020).
The diet became a popular treatment modality among those that suffered from seizure disorders until the advent of more recent anti-seizure medications–medications that have proven less sedating and better tolerated than those of the past (Kossoff & Cervenka, 2020). However, keto diets have seen a resurgence in popularity as both research has mounted regarding its efficacy to prevent seizures, and patient advocacy groups lent support for the diet as a non-drug therapy for seizure disorders. Today, keto diets continue to be researched in different variations and are offered to patients around the world as a means of taking control of their lives to prevent seizures (Kossoff & Cervenka, 2020).

Research is exploring the use of the ketogenic diet for other neurological disorders such as migraine headaches, Alzheimer’s disease, brain tumors, autism, among others. The research is still in early stages in these areas (Barbanit et al., 2017). Nonetheless, there does appear to be promise for reduction in symptoms for a variety of neurological disorders.
So what does this have to do with the other 99.9% of the people who put themselves on the keto diet? Researchers who support the use of the ketogenic diet in their clinics caution that the diet is a medical therapy for specific medical conditions and those following the diet need to be monitored for side effects and various nutrient deficiencies (Kossoff & Cervenka, 2020). So why are so many people adopting the keto diet for weight loss, or for “health?” What are the downsides?
Ketogenic diet, diabetes, and weight loss–a short term “fix,” long term problems
Keto diets have proven effective in producing SHORT TERM improvements in body composition and promoting weight loss…with an average weight loss of 5% of total body weight within 5-6 months (Fenasse & McEwen, 2019). Along with weight loss, improvements in insulin sensitivity, improved fasting glucose levels, and stability in blood sugars during the short term have also been demonstrated. However, the problem with all of this is that long term success rates with ketogenic diets is poor, with most people resuming their prior lifestyles and diets that led them into their poor states of health in the first place (Brouns, 2018); Fenasse & McEwen, 2019).
Keto diet downsides and risks
The keto diet not only has poor long term success rates as a treatment for obesity along with unproven long term effects on diabetes, there are additional downsides associated with the keto diet. Note, a number of these risks listed are from journal articles that FAVOR the use of keto diets for neurological conditions:
- Significantly increased risk of vitamin, mineral, and nutritional deficiencies requiring routine lab monitoring and supplementation during adherence to diet. Deficiencies can include selenium, calcium, magnesium, zinc, phosphorus, iron, copper, vitamin D, B-vitamins (found in grains), carnitine, as well as fiber
- Increased frequency of constipation due to reduced bowel motility and low fiber
- Increased risk of gastroesophageal reflux disease (GERD)
- Increases in cholesterol and triglyceride levels, with total cholesterol frequently climbing over 200mg/ dl during early months of keto diets (these levels may return to normal after a year)
- Increases in mortality (death) rates in those adhering to low carbohydrate diets
- Increased shift towards an acid state due to increased ketone bodies with subsequent weakening of skeletal tissue
- Increased fracture risk
- Regain of the weight lost starting after about 5-6 months on average (due to poor compliance rates)
- Decreased sports performance in sports requiring short bursts of activity (anaerobic exercise)
- Increase blood vessel stiffness and dysfunction
- Growth deficiencies in children following the keto diet
- Pancreatitis (inflammation of the pancreas)
- Cardiomyopathy (weakened heart)
- Increased risk of kidney stones
- Increased homocysteine–a risk factor for cardiovascular disease
- Increased intestinal permeability, allowing toxins and bacteria in the gut to leak into the blood stream (due to reduced fiber and dysregulation of the gut microbiota) (Brouns, 2018; Fenasse & McEwen, 2019; Kossoff & Cervenka, 2020; Kossoff et al., 2019)

Prolonged exposure to high fat diets: Complications
If the above effects aren’t frightening enough, dangers of adhering to diets high in fat over the long term include additionally:
- Liver damage
- Increased risk of various cancers
- Negative effects on mental health and well being
- Inflammation
- Worsened brain function
- Osteoporosis
- Metabolic dysfunction (increased blood pressure, blood sugar, body fat, and cholesterol)
- Increased cardiovascular disease prevalence
Keto diets are designed for specific purposes with medical oversight
As I note above, the side effects, risks, and complications listed above actually come from journal articles that favor the use of keto diets for persons with seizure disorders. In other words, these are not random people “hating on keto.” Rather, these are findings of the very researchers and health care providers who prescribe these diets. These diets due to their risks require close collaboration with medical teams so as to make adjustments, tailor the diets, order labs and diagnostic exams, and adjust the diets based on individual responses. For the general public to arbitrarily adopt these diets for their “health” makes ZERO sense.
If not keto, then what?
If you are looking for an dietary pattern that is sustainable, has high rates of success for short and long-term weight management, REDUCES (not increases) risk for diabetes, cancer, cardiac disease, inflammation, reverses disease in some cases, and has high rates of long-term compliance, then whole-food plant-based diets offer a far better option (Brouns, 2018). Says who, me? Yes, but says also the World Health Organization, the Dutch Health Council, the German Food Council, the Nordic Dietary Recommendations, and the Scientific Advisory Committee on Nutrition in England (Brouns, 2018, p 1309, para 3).
Not only that, but such diets have already been proven across the globe as noted among the world’s longest living, healthiest population groups (Bluezones.com, 2020). Based on research, diets high in legumes, fruits, vegetables, whole grains, along with moderate amounts of healthy fats such as those found in nuts, alvocados, olive oil, and other sources have proven themselves to be the healthiest option as noted by experts across the globe (Brouns, 2018). Throw in physical activity and a meal/ snack frequency of 2-4 “meals” total per day. Front load your calories with your largest meals early in the day, and a fasting window of 12-13 hours routinely overnight, and you will have your hormones, circadian rhythm, diet, and bowel microbiota all syncing together to produce a more optimal health and weight status (Longo, 2018).
Summary
Want short-term, temporary weight loss accompanied by increased constipation, increased cholesterol, increased inflammation, decreased blood-vessel function, and increased risks of long-term health complications? If so, keto is for you! If you have an underlying neurological condition, a keto diet may be managed as an option for you in collaboration with a qualified health care team that can regularly monitor your lab values and health status, making adjustments as necessary. For the vast majority of the population, a whole-food (minimally processed), plant-based diet makes far more sense. When a friend tells you to “do keto!,” remember, just say “NO!” 😉
Related posts
Evidence at a Glance: Plant-Based Diet Benefits
Plant-Based Diet: Claims, Evidence, and…What do the Scriptures Say?
Meal Timing, Meal Frequency, Fasting, & Health
A Brief Commentary on Popular Diet Trends and their Absurdities
References
Barbanti, P., Fofi, L., Aurilia, C., Egeo, G., & Caprio, M. (2017). Ketogenic diet in migraine: rationale, findings and perspectives. Neurological Sciences, 38, 111–115. https://doi-org.lopesalum.idm.oclc.org/10.1007/s10072-017-2889-6
Bluezones.com. (2020). Food guidelines. Retrieved from https://www.bluezones.com/recipes/food-guidelines/
Brouns F. (2018). Overweight and diabetes prevention: is a low-carbohydrate-high-fat diet recommendable?. European journal of nutrition, 57(4), 1301–1312. https://doi.org/10.1007/s00394-018-1636-y
Fenasse, R., & McEwen, B. (2019). The Ketogenic diet: a brief report. Journal of the Australian Traditional-Medicine Society, 25(1), 23–24. Retrieved from http://web.b.ebscohost.com.lopesalum.idm.oclc.org/ehost/pdfviewer/pdfviewer?vid=15&sid=041935ce-42c7-4068-a9ff-1f83174f996b%40pdc-v-sessmgr06
Kossoff, E., & Cervenka, M. (2020). Ketogenic Dietary Therapy Controversies for Its Second Century. Epilepsy Currents, 20(3), 125–129. https://doi-org.lopesalum.idm.oclc.org/10.1177/1535759719890337
Kossoff, E. H., Zupec-Kania, B. A., Auvin, S., Ballaban-Gil, K. R., Christina Bergqvist, A. G., Blackford, R., Buchhalter, J. R., Caraballo, R. H., Cross, J. H., Dahlin, M. G., Donner, E. J., Guzel, O., Jehle, R. S., Klepper, J., Kang, H. C., Lambrechts, D. A., Liu, Y., Nathan, J. K., Nordli, D. R., Jr, Pfeifer, H. H., … Practice Committee of the Child Neurology Society (2018). Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group. Epilepsia open, 3(2), 175–192. https://doi.org/10.1002/epi4.12225
Longo, V. (2018). The Longevity Diet. New York, NY: Penguin Random House